Traffic communicated in a communication network, e.g., a cellular network, may often be asymmetrical in time or cell domains. For instance, the amount of Downlink (DL) and Uplink (UL) traffic may be significantly different and may vary in time and/or across different cells. Such traffic variation may be handled effectively, for example, by adapting the amount of time resources assigned to the DL and the UL, e.g. using different Time Division Duplexing (TDD) frame configurations.
TDD offers flexible deployments without requiring a pair of spectrum resources. For TDD deployments in general, interference between UL and DL including both Base Station (BS) to BS and User Equipment (UE) to UE interference needs to be considered. One example includes layered heterogeneous network deployments, where it may be of interest to consider different uplink-downlink configurations in different cells. Also of interest are deployments involving different carriers deployed by different operators in the same band and employing either the same or different uplink-downlink configurations, where possible interference may include adjacent channel interference as well as co-channel interference such as remote BS-to-BS interference.
Currently, Long-Term-Evolution (LTE) TDD allows for asymmetric UL-DL allocations by providing a semi-static allocation utilizing seven different semi-statically configured uplink-downlink configurations. The semi-static allocation may or may not match the actual instantaneous traffic situation.